A six-year, longitudinal, school-based, preventive intervention is in its final year of implmentation. This project has involved two cohorts of students and a subsample of parents, beginning when these students entered their sixth grades and followed for two subsequent interventions in their eighth/ninth and tenth/eleventh grades. Measures of students' and parents' skill acquisition have been obtained at the completion of each intervention, and students have completed a substance use survey on an annual basis. The reasons for seeking continued support are to complete the final set of data analyses and reporting regarding the effectiveness of this multiyear, preventive intervention, to complete the longitudinal assessment of student substance use through the twelfth grade, and to conduct an assessment of key risk factors with a subsample of students and their parents. Therefore, the proposal has two primary specific aims. The first is to examine the effectiveness of the program interventions by: a) completing the final set of data analyses rgarding the effectiveness of the student and parent interventions in enhancing skill development and in reducing rates of student substance abuse; and b) conducting an additional assessment of risk factors in order to examine the differential effectiveness of the interventions with high, moderate, and low risk students based on measurement of prior and current school performance and school adjustment and of selected family factors. The second aim is to complete the longitudinal, epidemiological assessment of adolescent substance use across seven years (sixth to twelfth grades) in order to: a) derive an epidemiological profile of substance use patterns across time; and b) determine those factors most predictive of more extensive substance use among adolescents. Analyses of program effectiveness and assessment of risk factors are two critical areas of research in the prevention field. The present study will contribute to this body of knowledge by examining the differential effectiveness of interventions on the basis of timing of intervention, number of interventions, and selected individual student and family risk factors. In addition, analysis of the longitudinal survey data provides an excellent opportunity for testing theories regarding the development of adolescent substance use and for determining the relative contribution of various risk factors as predictors of later substance use.